<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <script>
        /* 
            需求分析:
                1. 提示用户输入一个数
                2. 判断,如果小于10,则补零
        */
        let num = prompt('请输入一个数');
        // if(num < 10){
        //     num = '0' + num;
        // } else{
        //     num;
        // }

        num = num < 10 ? '0' + num : num;

        console.log(num);
    </script>
</body>

</html>